Magnetic encoders are typically utilized to determine a position of a moving object in a mechanical system so the position or movement of the object can be controlled in the mechanical system. Magnetic encoders typically include a target, including dual multi-pole magnetic tracks, mounted on the moving object and magnetic sensors (e.g., strings of Hall-effect devices) placed in proximity to the poles of the respective magnetic tracks. The pole spacing of the respective magnetic tracks is typically different to induce a phase difference in the signals detected by the magnetic sensors over the respective tracks. The phase difference between the respective signals of the magnetic sensors is then utilized to determine the position of the target, and therefore the movable object, at any given time. In other words, the position of one of the magnetic tracks (i.e., the “measured track”) can be determined by comparing the signal output by the magnetic sensor over the measured track and the signal output by the magnetic sensor over the other track (i.e., the “reference track”).
Depending upon the control system with which a magnetic encoder is utilized, a decimal output or a binary output by the encoder may be desired. In such cases where a decimal output is desired, a magnetic encoder can be configured with a measured track having a particular number of North/South pole pairs (hereinafter “pole pairs”) and magnetic sensors having a particular resolution (i.e., “counts” or “edges” per pole pair) to yield a total number of counts or edges per revolution of a measured track that is divisible by 10, 100, and so on to yield a whole number of counts per revolution. For example, a resolution of 1000 counts per revolution of the measured track is often desired when a magnetic encoder is configured for decimal output. Such a resolution can be achieved by providing a target having a 25 pole-pair measured track, a 24 pole-pair reference track, and magnetic sensors having a resolution of 160 counts per pole pair (i.e., 25 pole pairs×160 counts/pole pair=4000 total counts per revolution of the measured track; then dividing by 4 to achieve the desired resolution of 1000 counts per revolution of the measured track).
In such cases where a binary output is desired, a magnetic encoder can be configured with a measured track having a particular number of pole pairs and magnetic sensors having a particular resolution to yield a total number of counts or edges per revolution of a measured track that is a factor of 2 to yield a binary number of counts per revolution. For example, a resolution of 1024 counts per revolution of the measured track is often desired when a magnetic encoder is configured for binary output. Such a resolution can be achieved by providing a target having a 32 pole-pair measured track, a 31 pole-pair reference track, and magnetic sensors having a resolution of 128 counts per pole pair (i.e., 32 pole pairs×128 counts/pole pair=4096 total counts per revolution of the measured track; then dividing by 4 to achieve the desired resolution of 1024 counts per revolution of the measured track).